package com.example.mymessagequeue.mqclient;

import com.example.mymessagequeue.common.*;
import com.example.mymessagequeue.mqserver.core.BasicProperties;
import com.example.mymessagequeue.mqserver.core.ExchangeType;

import java.io.IOException;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.ConcurrentHashMap;

public class Channel {
    private String channelId;

    // 当前这个 channel 属于哪个连接
    private Connection connection;

    // 用来存储后续客户端收到的服务器的响应
    private ConcurrentHashMap<String, BasicReturns> basicReturnsMap = new ConcurrentHashMap<>();

    // 如果当前 Channel 订阅了某个队列，就需要在此处记录下对应回调是啥，当该队列的消息返回回来的时候，调用回调
    // 此处约定一个 Channel 只能有一个回调
    private Consumer consumer = null;

    public Channel(String channelId, Connection connection) {
        this.channelId = channelId;
        this.connection = connection;
    }

    /**
     * 与服务器交互，告知服务器，此处客户端创建了新的 channel
     *
     * @return
     */
    public boolean createChannel() throws IOException {
        // 对于创建 Channel 来说, payload 就是一个 basicArguments 对象
        BasicArguments basicArguments = new BasicArguments();
        basicArguments.setChannelId(channelId);
        basicArguments.setRid(generateRid());
        byte[] payload = BinaryTool.toBytes(basicArguments);

        Request request = new Request();
        request.setType(0x1);
        request.setLength(payload.length);
        request.setPayload(payload);

        connection.writeRequest(request);
        // 等待服务器响应
        BasicReturns basicReturns = waitResult(basicArguments.getRid());
        return basicReturns.isOk();
    }

    /**
     * 使用这个方法来阻塞等待服务器的响应
     * @param rid
     * @return
     */
    private BasicReturns waitResult(String rid) {
        BasicReturns basicReturns = null;
        while ((basicReturns = basicReturnsMap.get(rid)) == null) {
            // 如果查询结果为 null，说明服务器响应还没回来
            // 此时就需要阻塞等待.
            synchronized (this) {
                try {
                    wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
        // 读取成功后删除这个响应
        basicReturnsMap.remove(rid);
        return basicReturns;
    }


    public void putReturns(BasicReturns basicReturns) {
        basicReturnsMap.put(basicReturns.getRid(), basicReturns);
        synchronized (this) {
            // 当前不知道有多少个线程在等待上述的这个响应
            // 所以此时把所有的线程都唤醒
            notifyAll();
        }
    }

    private String generateRid() {
        return "R-" + UUID.randomUUID().toString();
    }


    /**
     * 关闭 channel 给服务器发送 type 为 0x2 的请求
     *
     * @return
     */
    public boolean close() throws IOException {
        BasicArguments basicArguments = new BasicArguments();
        basicArguments.setChannelId(channelId);
        basicArguments.setRid(generateRid());
        byte[] payload = BinaryTool.toBytes(basicArguments);

        Request request = new Request();
        request.setType(0x2);
        request.setLength(payload.length);
        request.setPayload(payload);

        connection.writeRequest(request);
        // 等待服务器响应
        BasicReturns basicReturns = waitResult(basicArguments.getRid());
        return basicReturns.isOk();
    }

    /**
     * 创建一个交换机, 远程方法调用
     *
     * @param exchangeName
     * @param exchangeType
     * @param durable
     * @param autoDelete
     * @param arguments
     * @return
     */
    public boolean exchangeDeclare(String exchangeName, ExchangeType exchangeType, boolean durable, boolean autoDelete,
                                   Map<String, Object> arguments) throws IOException {
        ExchangeDeclareArguments exchangeDeclareArguments = new ExchangeDeclareArguments();
        exchangeDeclareArguments.setRid(generateRid());
        exchangeDeclareArguments.setChannelId(channelId);
        exchangeDeclareArguments.setExchangeName(exchangeName);
        exchangeDeclareArguments.setExchangeType(exchangeType);
        exchangeDeclareArguments.setDurable(durable);
        exchangeDeclareArguments.setAutoDelete(autoDelete);
        exchangeDeclareArguments.setArguments(arguments);
        byte[] payload = BinaryTool.toBytes(exchangeDeclareArguments);

        Request request = new Request();
        request.setType(0x3);
        request.setLength(payload.length);
        request.setPayload(payload);

        connection.writeRequest(request);
        BasicReturns basicReturns = waitResult(exchangeDeclareArguments.getRid());
        return basicReturns.isOk();
    }

    /**
     * 删除交换机，远程方法调用
     *
     * @param exchangeName
     * @return
     */
    public boolean exchangeDelete(String exchangeName) throws IOException {
        ExchangeDeleteArguments exchangeDeleteArguments = new ExchangeDeleteArguments();
        exchangeDeleteArguments.setRid(generateRid());
        exchangeDeleteArguments.setChannelId(channelId);
        exchangeDeleteArguments.setExchangeName(exchangeName);
        byte[] payload = BinaryTool.toBytes(exchangeDeleteArguments);

        Request request = new Request();
        request.setType(0x4);
        request.setLength(payload.length);
        request.setPayload(payload);

        connection.writeRequest(request);

        BasicReturns basicReturns = waitResult(exchangeDeleteArguments.getRid());
        return basicReturns.isOk();
    }

    /**
     * 创建交换机，远程方法调用
     *
     * @param queueName
     * @param durable
     * @param exclusive
     * @param autoDelete
     * @param arguments
     * @return
     */
    public boolean queueDeclare(String queueName, boolean durable, boolean exclusive, boolean autoDelete,
                                Map<String, Object> arguments) throws IOException {
        QueueDeclareArguments queueDeclareArguments = new QueueDeclareArguments();
        queueDeclareArguments.setRid(generateRid());
        queueDeclareArguments.setChannelId(channelId);
        queueDeclareArguments.setQueueName(queueName);
        queueDeclareArguments.setDurable(durable);
        queueDeclareArguments.setExclusive(exclusive);
        queueDeclareArguments.setAutoDelete(autoDelete);
        queueDeclareArguments.setArguments(arguments);
        byte[] payload = BinaryTool.toBytes(queueDeclareArguments);

        Request request = new Request();
        request.setType(0x5);
        request.setLength(payload.length);
        request.setPayload(payload);

        connection.writeRequest(request);

        BasicReturns basicReturns = waitResult(queueDeclareArguments.getRid());
        return basicReturns.isOk();
    }

    /**
     * 删除队列，远程方法调用
     * @param queueName
     * @return
     */
    public boolean queueDelete(String queueName) throws IOException {
        QueueDeleteArguments queueDeleteArguments = new QueueDeleteArguments();
        queueDeleteArguments.setRid(generateRid());
        queueDeleteArguments.setChannelId(channelId);
        queueDeleteArguments.setQueueName(queueName);
        byte[] payload = BinaryTool.toBytes(queueDeleteArguments);

        Request request = new Request();
        request.setType(0x6);
        request.setLength(payload.length);
        request.setPayload(payload);

        connection.writeRequest(request);

        BasicReturns basicReturns = waitResult(queueDeleteArguments.getRid());
        return basicReturns.isOk();
    }

    /**
     * 创建绑定，远程方法调用
     * @param queueName
     * @param exchangeName
     * @param bindingKey
     * @return
     */
    public boolean queueBind(String queueName, String exchangeName, String bindingKey) throws IOException {
        QueueBindArguments queueBindArguments = new QueueBindArguments();
        queueBindArguments.setRid(generateRid());
        queueBindArguments.setChannelId(channelId);
        queueBindArguments.setQueueName(queueName);
        queueBindArguments.setExchangeName(exchangeName);
        queueBindArguments.setBindingKey(bindingKey);
        byte[] payload = BinaryTool.toBytes(queueBindArguments);

        Request request = new Request();
        request.setType(0x7);
        request.setLength(payload.length);
        request.setPayload(payload);

        connection.writeRequest(request);

        BasicReturns basicReturns = waitResult(queueBindArguments.getRid());
        return basicReturns.isOk();
    }

    /**
     * 解除绑定远程方法调用
     * @param queueName
     * @param exchangeName
     * @return
     */
    public boolean queueUnbind(String queueName, String exchangeName) throws IOException {
        QueueUnbindArguments queueUnbindArguments = new QueueUnbindArguments();
        queueUnbindArguments.setRid(generateRid());
        queueUnbindArguments.setChannelId(channelId);
        queueUnbindArguments.setQueueName(queueName);
        queueUnbindArguments.setExchangeName(exchangeName);
        byte[] payload = BinaryTool.toBytes(queueUnbindArguments);

        Request request = new Request();
        request.setType(0x8);
        request.setLength(payload.length);
        request.setPayload(payload);

        connection.writeRequest(request);

        BasicReturns basicReturns = waitResult(queueUnbindArguments.getRid());
        return basicReturns.isOk();
    }

    /**
     * 发布消息，远程方法调用
     * @param exchangeName
     * @param routingKey
     * @param basicProperties
     * @param body
     * @return
     */
    public boolean basicPublish(String exchangeName, String routingKey, BasicProperties basicProperties, byte[] body) throws IOException {
        BasicPublishArguments basicPublishArguments = new BasicPublishArguments();
        basicPublishArguments.setRid(generateRid());
        basicPublishArguments.setChannelId(channelId);
        basicPublishArguments.setExchangeName(exchangeName);
        basicPublishArguments.setRoutingKey(routingKey);
        basicPublishArguments.setBasicProperties(basicProperties);
        basicPublishArguments.setBody(body);

        byte[] payload = BinaryTool.toBytes(basicPublishArguments);

        Request request = new Request();
        request.setType(0x9);
        request.setLength(payload.length);
        request.setPayload(payload);

        connection.writeRequest(request);

        BasicReturns basicReturns = waitResult(basicPublishArguments.getRid());
        return basicReturns.isOk();
    }

    /**
     * 消费消息
     * @param queueName
     * @param autoAck
     * @param consumer
     * @return
     * @throws MqException
     * @throws IOException
     */
    public boolean basicConsume(String queueName, boolean autoAck, Consumer consumer) throws MqException, IOException {
        // 先设置回调
        if (this.consumer != null) {
            throw new MqException("该 channel 已经设置过消费消息的回调了, 不能重复设置!");
        }
        this.consumer = consumer;

        BasicConsumeArguments basicConsumeArguments = new BasicConsumeArguments();
        basicConsumeArguments.setRid(generateRid());
        basicConsumeArguments.setChannelId(channelId);
        basicConsumeArguments.setConsumerTag(channelId);
        basicConsumeArguments.setQueueName(queueName);
        basicConsumeArguments.setAutoAck(autoAck);
        byte[] payload = BinaryTool.toBytes(basicConsumeArguments);

        Request request = new Request();
        request.setType(0xa);
        request.setLength(payload.length);
        request.setPayload(payload);

        connection.writeRequest(request);

        BasicReturns basicReturns = waitResult(basicConsumeArguments.getRid());
        return basicReturns.isOk();
    }


    /**
     * 确认消息
     * @param queueName
     * @param messageId
     * @return
     */
    public boolean basicAck(String queueName, String messageId) throws IOException {
        BasicAckArguments basicAckArguments = new BasicAckArguments();
        basicAckArguments.setRid(generateRid());
        basicAckArguments.setChannelId(channelId);
        basicAckArguments.setQueueName(queueName);
        basicAckArguments.setMessageId(messageId);
        byte[] payload = BinaryTool.toBytes(basicAckArguments);

        Request request = new Request();
        request.setType(0xb);
        request.setLength(payload.length);
        request.setPayload(payload);

        connection.writeRequest(request);

        BasicReturns basicReturns = waitResult(basicAckArguments.getRid());
        return basicReturns.isOk();
    }

    public String getChannelId() {
        return channelId;
    }

    public void setChannelId(String channelId) {
        this.channelId = channelId;
    }

    public Connection getConnection() {
        return connection;
    }

    public void setConnection(Connection connection) {
        this.connection = connection;
    }

    public ConcurrentHashMap<String, BasicReturns> getBasicReturnsMap() {
        return basicReturnsMap;
    }

    public void setBasicReturnsMap(ConcurrentHashMap<String, BasicReturns> basicReturnsMap) {
        this.basicReturnsMap = basicReturnsMap;
    }

    public Consumer getConsumer() {
        return consumer;
    }

    public void setConsumer(Consumer consumer) {
        this.consumer = consumer;
    }

}
